diff --git a/src/validate_block.cpp b/src/validate_block.cpp
index f9e14646..6ecb73ad 100644
--- a/src/validate_block.cpp
+++ b/src/validate_block.cpp
@@ -251,6 +251,7 @@ bool validate_block::is_distinct_tx_set(const transaction_list& txs)
 
     std::vector<hash_digest> hashes(txs.size());
     std::transform(txs.begin(), txs.end(), hashes.begin(), hasher);
+    std::sort(hashes.begin(), hashes.end());
     auto distinct_end = std::unique(hashes.begin(), hashes.end());
     return distinct_end == hashes.end();
 }
diff --git a/test/validate_block.cpp b/test/validate_block.cpp
index e66c26d5..e3330ad6 100644
--- a/test/validate_block.cpp
+++ b/test/validate_block.cpp
@@ -159,6 +159,14 @@ BOOST_AUTO_TEST_CASE(validate_block__is_distinct_tx_set__partialy_distinct_by_ve
     BOOST_REQUIRE(!validate_block_fixture::is_distinct_tx_set({ tx1, tx2, tx3 }));
 }
 
+BOOST_AUTO_TEST_CASE(validate_block__is_distinct_tx_set__partialy_distinct_not_adjacent_by_version__false)
+{
+    const transaction_type tx1{ 1, 0 };
+    const transaction_type tx2{ 2, 0 };
+    const transaction_type tx3{ 1, 0 };
+    BOOST_REQUIRE(!validate_block_fixture::is_distinct_tx_set({ tx1, tx2, tx3 }));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 BOOST_AUTO_TEST_SUITE_END()